Conventionally, Japanese Patent Laid-Open Publication No. 2002-75967 and H11-233495 disclose a method of performing a plasma processing on a multilayer film which includes a metal layer. In the plasma processing method disclosed in Japanese Patent Laid-Open Publication No. 2002-75967, an etching processing is performed on an workpiece which includes a metal layer (a tungsten nitride layer or a titanium nitride layer) formed on a polysilicon layer, a tungsten layer formed on the metal layer, and a silicon oxide formed on the tungsten layer. The tungsten layer is etched by using the silicon oxide, and then the metal layer formed on the polysilicon layer is etched by using a mixed gas of a gas containing atoms of at least one of fluorine, chlorine and bromine, and a gas containing oxygen atoms. The polysilicon layer is etched by a chlorine gas or a hydrogen bromide gas.
In the plasma processing method disclosed in Japanese Patent Laid-Open Publication No. H11-233495, an etching processing is performed on a workpiece in which a polysilicon layer, a metal layer or a metal silicide layer, and a mask pattern are sequentially layered on a substrate. The method includes a first process of etching the metal layer or the metal silicide layer by using a gas containing fluorine, chlorine and bromine, a second process of removing an etching interference film formed on the polysilicon layer, and a third process of etching the polysilicon layer by using a gas containing chlorine.